Clamp



March 3, 1964 A. |-:'ro ETAL CLAMP 2 Sheets-Sheet 1 Filed April 20 1961 Fl G. 2

: INVENTORS ALFONSO LETO By FRANK LETO ATTORNEY March 3, 1964 A. LETO ETAL 3,

CLAMP Filed April 20, 1961 2 Sheets-Sheet 2 INVENTOR. ALFON SO LETO By FRANK LETO ATTORN EY United States Patent O 3,123,426 CLAMP Alfonso Leto, Woodland Hills, and Frank Leto, Panorama City, Calif., assigrrors to The Pipetron Company, a partnership Filed Apr. 20, 1961, Ser. No. 104,401 6 Claims. (Cl. 339-251) This invention relates to a novel and improved clamp and more particularly to a novel and improved electrical contact clamp which can be quickly and positively attached to and detached from a cylindrical body such as a pipe or conduit.

One object of this invention is to provide an electrical contact clamp which connects or attaches an electrical cable to any sized or shaped cylindrical object such as a pipe or conduit, for the purpose of providing positive electrical contact to said object permitting arc welding or the like.

Another object of this invention is to provide an electrical contact clamp that can quickly be attached to and detached from cylindrical objects of various sizes.

A further object of this invention is to provide an electrical contact clamp which can be used for arc welding, jumpering across sections of pipe being removed, shorting out insulating fittings temporarily and cathodic protection measurements.

Other objects and advantages of this invention will become apparent when taken in connection with the accompanying claims and drawings in which:

FIG. 1 shows a perspective view of a clamp embodying this invention affixed to a pipe;

FIG. 2 is an end view of a clamp embodying this invention shown in FIG. 1 and illustrates how a single clamp can be used for pipes varying in size from small to very large;

FIG. 3 shows a side elevational view illustrating the clamp embodying this invention with the chain in a long position; and

FIG. 4 shows a side elevational view of a clamp em bodying this invention with the chain in a short position.

Briefly described, this invention comprises an electrical contact clamp having an elongated body with a chain retaining means, a tightening member such as a screw on one end thereof for tightening said chain and a pair of spaced apart feet on the end opposite said screw, said feet being arcuate in both longitudinal and transverse directions for the purpose of presenting a curved non-gau ing surface to the cylinder to which it is attached.

Turning now to a detailed description of a clamp embodying this invention. The numeral 2 designates generally the body portion of the clamp which is made of any electrically conductive metal such as bronze. The numeral 4 designates generally a cylindrical body such as a pipe or other conduit to which the clamp 2 is attached. The numeral 6 designates an electrical cable affixed to the body 2 of the clamp by means of a bolt 8. The under side 10 of the body portion 2 of the clamp is made slightly arcuate along its longitudinal length, the purpose for which will be described later. This material should be of a softer material than the conduit material to which it is attached to prevent weakening of the conduit.

On one end of the body portion 2 there is provided a collar nut 12 through which a bolt 14 is provided with a handle 16 and at the opposite end with a conventional floating foot 18 which if desirable may be provided with serrations 20, as shown, for the purpose of preventing slipping or may be shaped in any desired manner to facilitate centering of the clamp on the cylinder.

Intermediate to the ends of the body portion 2 there is provided a pair of lugs 22 to which is pivotally at- 3,,lZ3AZh Patented Mar. 3, 1964 'ice tached a chain 24 by means of a pin 26. A second pair of spaced apart lugs 28 is also provided on the body 2, as shown in FIG. 1, forming a notch 29 so spaced in more or less conventional manner as to detachably receive a link 30 of chain 24.

As will be apparent, the chain 24 is thrown around the pipe 4 quickly and is drawn as tightly as practicable by hand with a link 36 dropped into notch 29 which locks the chain around the pipe 4. The screw 14 is then tightened through the collar nut 12 lifting that end of the body portion 2 away from the pipe or conduit 4, which draws chain 24 tight and locks the clamp firmly onto the pipe. While a screw 14 has been here illustrated, it is to be understood that this has been found to be the more satisfactory in practice, but a cam-lock or other tightening means could also be used.

On the end of the body portion 2, opposite the collar nut 12, is provided a pair of feet 32. Each of the feet 32 are constructed identically and both feet are provided with elongated serrations 34.

The outer surface formed by the elongated serrations 34 are formed into transverse arcuate curve 36, as more clearly shown in FIG. 2. While the specific radius of the curve 36 is not critical, in order to adequately carry out the teachings of this invention, a radius for this curve must be chosen of such length so as to provide an are greater than the arc of the smallest conduit to which the clamp is to be afiixed and, as shown in FIG. 2, this are should be of such a length and curvature to present at least two of the elongated serrations 34 to the conduit surface when clamped tight.

Again, it is pointed out that the pair of feet 32 are spaced. apart. While theparticular inside and outside spacing between the pair of feet 32 is not critical, as will be seen from studying FIG. 2, they must be spaced apart in proportion to the selected radius and length of are 36 relative to the arc of the smallest contemplated conduit to which the clamp is to be attached to prevent gauging by the serrations 34 and to afford a maximum surface for the electrical contact and with a minimum resistance at the point of contact.

Attention is next directed to the feet 32 in their longitudinal direction when regarded from the side as shown in FIGS. 3 and 4. Here again, each of the pair of feet 32 are formed in an arcuate curve 38. Again, the particular radius of the curve 38 is not critical, but in order to fully carry out the spirit of this invention, it must be such as to provide an are which will permit the body of the clamp to pivot within the limits of the screw 14 without permitting either end of the foot to gauge into the pipe 4 when the clamp is in its maximum raised position as shown in FIG. 3 or in its lowest position as shown in FIG. 4.

Turning now to an explanation of the operation of the clamp embodying this invention. The electrical cable 6 is connected to an arc Welding or other electrical system or circuit not shown, and positive electrical contact between the cable 6 and the clamp body 2 is provided in a conventional manner by means of the bolt 8. The readily and quickly detachable feature of this clamp being made possible by virtue of the combination of the chain 24, the pair of lugs 28 and link 30 and the tightening action of bolt 14. It is of importance that this clamp give a positive electrical contact between the cable 6, the clamp body 2 and the conduit 4. For this reason, the cable 6 is attached to clamp 2 as closely adjacent the pair of feet 32 as practicable to provide as short a bus as possible through the clamp. The contact between the clamp and the pipe 4 with the feet 32 positioned and spaced as described, af ford a positive electrical contact with the conduit 4 and at the same time inherently avoids damage to the conduit ,1 d by gauging or the like but still permits a positive electrical contact with the pipe 4.

As can be seen from studying the illustrations shown in FIGS. 2, 3 and 4, the transverse and longitudinal curvature of the feet 32 provide, regardless of the particular position of the clamp body 2 in relation to the conduit 4, a maximum equivalent surface contact of both of the feet 32 on the conduit 4. The center of both arcuate curves must lie outside the conduit to which the clamp is to be attached.

ft is also to be noted that while the clamp embodying this invention is illustrated in connection with a pipe or a cylindrical surface it is to be understood that this clamp is also, because of its three point contact, equally adaptable to most irregular surfaces.

It is also to be understood that modifications in shape, size, material etc. can be resorted to without departing from the spirit of this invention as set forth in the appended claims.

I claim:

1. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, each of said feet being arcuate on the surface thereof in a direction longitudinal of said body, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain and adjusting means on the end of said body opposite said pair of feet adapted to bear against said conduit and to lift said end of said body opposite said feet away from said conduit and to pivot said body on said arcuate feet, against said chain and thereby to force said arcuate feet against said conduit as said adjusting means is actuated against said conduit.

2. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, the surface of each of said feet being arcuate in a direction transverse to the center axis of said elongated body and with the center of said curve of said are lying in a plane outside the surface of the conduit to which the clamp is to be attached, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain and adjusting means on the end of said body opposite said pair of feet adapted to bear against said conduit and to lift said end of said body opposite said feet away from said conduit and to pivot said body on said arcuate feet, against said chain and thereby to force said arcuate feet against said conduit as said adjusting means is actuated against said conduit.

3. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, the surface of said feet being arcuate in both a longitudinal and a transverse direction to the center axis of said elongated body and with the centers of said curves of said arcs both lying in a plane outside the surface of the conduit to which the clamp is to be attached, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain and adjusting means on the end of said body opposite said pair of feet adapted to lift one end of said body away from said conduit and to pivot said body on said feet and against said chain.

4. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, the surface of said feet being arcuate in both a longitudinal and a transverse direction to the center axis of said elongated body and with the centers of said curves of said arcs both lying in a plane outside the surface of the conduit to which the clamp is to be attached, fluted means on the surface of each of said feet extending longitudinally the length thereof, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain and adjusting means on the end of said body opposite said pair of feet adapted to lift one end of said body away from said conduit and to pivot said body on said feet and against said chain.

5. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, the surface of said feet being arcuate in both a longitudinal and a transverse direction to the center axis of said elongated body and with the centers of said curves of said arcs both lying in a plane outside the surface of the conduit to which the clamp is to be attached, fluted means on the surface of each of said feet extending longitudinally the length thereof, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain, electrical connecting means on said clamp located closely adjacent to said pair of feet and adjusting means on the end of said body opposite said pair of feet adapted to lift one end of said body away from said conduit and to pivot said body on said feet and against said chain.

6. An electrical connector clamp for attachment to a conduit comprising an elongated body, a pair of spaced apart feet on one end of said body, the surface of said feet being arcuate in both a longitudinal and a transverse direction to the center axis of said elongated body and with the centers of said curves of said arcs both lying in a'plane substantially Within said body and outside the surface of the conduit to which the clamp is to be attached, fluted means on the surface of each of said feet extending longitudinally the length thereof, a chain having one end thereof attached to said body intermediate the ends thereof, locking means on said body adapted to removably receive a link on said chain, electrical connecting means on said clamp located closely adjacent to said pair of feet, threads on the end of said body opposite said pair of feet and a screw in said threads adapted to pivot said body on said conduit about the longitudinal arcuate surface of said feet and against said chain when it is placed around said conduit thereby tightening said feet into positive electrical contact onto said conduit.

References Cited in the file of this patent UNITED STATES PATENTS 1,682,658 Bosco Aug. 28, 1928 1,860,116 Pearson May 24, 1932 1,932,602 Ratta Oct. 31, 1933 FOREIGN PATENTS FA. 1665 France l'uly 11, 1903 366,659 Italy Jan. 4, 1939 

3. AN ELECTRICAL CONNECTOR CLAMP FOR ATTACHMENT TO A CONDUIT COMPRISING AN ELONGATED BODY, A PAIR OF SPACED APART FEET ON ONE END OF SAID BODY, THE SURFACE OF SAID FEET BEING ARCUATE IN BOTH A LONGITUDINAL AND A TRANSVERSE DIRECTION TO THE CENTER AXIS OF SAID ELONGATED BODY AND WITH THE CENTERS OF SAID CURVES OF SAID ARCS BOTH LYING IN A PLANE OUTSIDE THE SURFACE OF THE CONDUIT TO WHICH THE CLAMP IS TO BE ATTACHED, A CHAIN HAVING ONE END THEREOF ATTACHED TO SAID BODY INTERMEDIATE THE ENDS THEREOF, LOCKING MEANS ON SAID BODY ADAPTED TO REMOVABLY RECEIVE A LINK ON SAID CHAIN AND ADJUSTING MEANS ON THE END OF SAID BODY OPPOSITE SAID PAIR OF FEET ADAPTED TO LIFT ONE END OF SAID BODY AWAY FROM SAID CONDUIT AND TO PIVOT SAID BODY ON SAID FEET AND AGAINST SAID CHAIN. 